1. Field of the Invention
This invention relates generally to the restraint of cargo and deals more particularly with an improved winch which serves to tighten tie-down straps of the type commonly used to secure cargo carried on flatbed trucks.
2. Description of the Related Art
Cargo that is transported on flatbed trucks and other vehicles is secured to the vehicle bed in a variety of different ways. One common cargo restraint system makes use of cargo straps which are tightened over the cargo in order to hold it down. One end of each strap is hooked or otherwise secured to one side of the truck bed. The straps are drawn over the cargo, and each is applied to a winch mounted on the opposite side of the cargo bed. The winch can be turned in a direction to wind the strap tightly on the winch drum in order to tighten the winch straps on the cargo. A ratchet wheel and a pivotal pawl cooperate to lock the winch drum such that the straps are retained in a tight condition in which they are able to effectively restrain the cargo.
Although this type of restraint system works well with many loads, it has not been without problems. Most notably, the teeth of the ratchet wheel or pawl can break and thus release the strap so that it is unable to restrain the cargo. In order to adequately tie down the cargo, each winch must be turned so that the straps are as tight as possible for maximum restraint of the load. However, because of the tight condition of the straps, the mating teeth of the ratchet wheel and pawl are subjected to considerable forces. The resulting stress can cause one or more teeth to fracture, thus causing failure of the restraint system.